CHEM 219 MODULE 2 ADVANCED EXAM
PREP MATERIAL WITH TESTED QUESTIONS
AND EXPERT SOLUTIONS
◉ Are alkanes soluble in water?
Answer: They are water-insoluble.
◉ Are alkanes polar or non-polar?
Answer: Almost non-polar
◉ What is hydrogen bonding?
Answer: The water molecules are attracted to each other like
magnets because of it's electron rich O atom possessing a -charge
and its electron poor H possessing a + charge
◉ What will a mixture of alkane and water make?
Answer: A two layer-biphasic system. It will float on top of water.
since its density is less than 1g/ml
◉ Are liquid alkanes used as solvents?
Answer: Yes for other non polar substances.
◉ When compared to other polar molecules of similar weight, are
alkanes lower or higher in melting and boiling points?
,Answer: They are lower.
◉ What are Van der Waals forces?
Answer: The attractive forces between molecules.
◉ The polarization in VDWF's are:
Answer: Temporary and weak
◉ What is the relationship between branching and VDWF?
Answer: As you branch out you gain more surface area and lower
the VDWF. Which lowers the BP and MP
◉ Alkanes can adopt different conformations, What does this
mean?
Answer: This means that it can change shapes as it can rotate
around bonds.
◉ Hydrogen bonding and VDWFS are classifies as nonbonding
intermolecular forces, what does this mean?
Answer: That they are attractive forces between molecules that
are not true bonds in the sense of sharing or donating.
◉ What are conformers?
Answer: Different shapes of molecules that are derived by
rotations of single bonds.
, ◉ What does the Newman projection do?
Answer: It shows the conformation of molecules when looking
down a particular bond axis.
◉ What is the difference in hydrogen placement between an
eclipsed confirmation and a staggered one?
Answer: The hydrogens do not overlap in staggered but they do in
eclipsed.
◉ Certain conformers are called rotamers, why?
Answer: They can simply be rotated into the other conformer.
Used with newman projections
◉ Staggered vs. Eclipsed Conformers
Answer: Staggered are generally more stable, because of the
removed repulsion that occurs when electrons are aligned on top
of each other in an eclipsed.
◉ How do you name newman projections?
Answer: Find the first carbon chain, attach it to the front carbon.
The rest are substituents. Then attach it to the back carbon. Then
attach the first carbon chain, the rest are substituents.
◉ Can conformers be isolated at room temp?
PREP MATERIAL WITH TESTED QUESTIONS
AND EXPERT SOLUTIONS
◉ Are alkanes soluble in water?
Answer: They are water-insoluble.
◉ Are alkanes polar or non-polar?
Answer: Almost non-polar
◉ What is hydrogen bonding?
Answer: The water molecules are attracted to each other like
magnets because of it's electron rich O atom possessing a -charge
and its electron poor H possessing a + charge
◉ What will a mixture of alkane and water make?
Answer: A two layer-biphasic system. It will float on top of water.
since its density is less than 1g/ml
◉ Are liquid alkanes used as solvents?
Answer: Yes for other non polar substances.
◉ When compared to other polar molecules of similar weight, are
alkanes lower or higher in melting and boiling points?
,Answer: They are lower.
◉ What are Van der Waals forces?
Answer: The attractive forces between molecules.
◉ The polarization in VDWF's are:
Answer: Temporary and weak
◉ What is the relationship between branching and VDWF?
Answer: As you branch out you gain more surface area and lower
the VDWF. Which lowers the BP and MP
◉ Alkanes can adopt different conformations, What does this
mean?
Answer: This means that it can change shapes as it can rotate
around bonds.
◉ Hydrogen bonding and VDWFS are classifies as nonbonding
intermolecular forces, what does this mean?
Answer: That they are attractive forces between molecules that
are not true bonds in the sense of sharing or donating.
◉ What are conformers?
Answer: Different shapes of molecules that are derived by
rotations of single bonds.
, ◉ What does the Newman projection do?
Answer: It shows the conformation of molecules when looking
down a particular bond axis.
◉ What is the difference in hydrogen placement between an
eclipsed confirmation and a staggered one?
Answer: The hydrogens do not overlap in staggered but they do in
eclipsed.
◉ Certain conformers are called rotamers, why?
Answer: They can simply be rotated into the other conformer.
Used with newman projections
◉ Staggered vs. Eclipsed Conformers
Answer: Staggered are generally more stable, because of the
removed repulsion that occurs when electrons are aligned on top
of each other in an eclipsed.
◉ How do you name newman projections?
Answer: Find the first carbon chain, attach it to the front carbon.
The rest are substituents. Then attach it to the back carbon. Then
attach the first carbon chain, the rest are substituents.
◉ Can conformers be isolated at room temp?
